How to install the macOS Mojave public beta on a separate APFS volume

APFS makes it easier than ever to test drive a prerelease version of macOS.

When you install the macOS Mojave beta on a separate volume of your hard drive, you can conveniently switch between Mojave and High Sierra on the same Mac, as if each were on a separate drive. And because the storage space used by the additional APFS volume is shared with your existing volume, you don't need to reserve space for the new volume. Its size automatically adjusts to fit your content.

What you need

To complete these steps, you need a Mac that has an all-flash storage device and macOS High Sierra. Make sure that you have at least 20GB of free space to install Mojave, plus any additional space needed for your files and apps. The space required to install Mojave and keep it up to date will vary throughout the beta release period.

Check About This Mac to see how much storage space is available, and check for ”Flash Storage” beneath the drive icon to confirm that you're using flash storage:

Back up your Mac

Beta software is software that is still in development, which means some apps and services might not work as expected. So it's important to back up your Mac before continuing. You can use Time Machine to make a backup.

Add an APFS volume

Open Disk Utility, which is in the Utilities folder of your Applications folder.

In the sidebar, select your existing APFS volume.

Choose Edit > Add APFS Volume from the menu bar, or click in the Disk Utility toolbar. These options are available only when an APFS volume is selected.

Type a name for the new APFS volume, then click Add:

Enroll your Mac and install the beta

Go to beta.apple.com and follow the instructions to enroll your Mac in the Apple Beta Software Program, download the Mojave beta installer, and begin installation.

When you're asked to choose where to install the beta, click Show All Disks and choose the volume you just created:

Or press and hold the Option key during startup, then choose the Mojave or High Sierra volume when prompted.

Keep the beta up to date

When your Mac is enrolled in Apple Beta Software Program, you will receive a notification when a new public beta is available. To check for updates or install the latest version, use the Software Update pane in System Preferences: